A new theoretical study from researchers at Queen Mary University of London offers a fresh way to examine one of physics’ most enduring mysteries: how the universe has evolved into an increasingly complex place while still following the second law of thermodynamics. The findings explore whether gravity itself may help explain how galaxies, stars, planets, and eventually life emerged without violating one of nature’s most fundamental principles.
New Research Examines the Link Between Gravity and Thermodynamics
Professor Ginestra Bianconi, a mathematician at Queen Mary University of London, presents the research in a paper published in Physical Review D. The study investigates the thermodynamic properties of the Gravity from Entropy (GfE) theory, an emerging approach to quantum gravity that describes gravity as arising from the microscopic structure of spacetime through principles of statistical mechanics.
The work addresses a longstanding question in cosmology. According to the second law of thermodynamics, the total entropy—or the overall measure often associated with disorder—of an isolated system increases over time. Albert Einstein regarded this law as one of the most fundamental principles in physics, famously stating that it occupies a unique place among the laws of nature.
Yet the observable universe appears to tell a more complicated story. Scientists believe the early universe began in a relatively low-entropy state, but over billions of years it has produced highly organized structures, including galaxies, stellar systems, planets, and ultimately living organisms. Explaining how this growing complexity can exist alongside ever-increasing entropy has remained a central challenge in modern physics.
How Gravity From Entropy Theory Works
Gravity as an Emergent Property
The Gravity from Entropy framework proposes that gravity is not a fundamental force in itself but instead emerges from the relationship between spacetime geometry and information.
Specifically, the theory describes gravity as arising from the information-theoretic difference between the true spacetime metric and the metric generated by matter fields and curvature. This relationship is represented mathematically through the Quantum Geometric Relative Entropy (QGRE), which forms the basis of the GfE Lagrangian.
Under conditions involving relatively low energy and weak spacetime curvature, the equations produced by GfE align with Einstein’s general theory of relativity. At higher energies or stronger curvature, however, the theory predicts departures from general relativity, including the appearance of a dynamic dark energy component that could potentially be tested through future observations.
Study Finds Different Behaviors for Total and Local Entropy
One of the study’s key findings is that total entropy and local entropy behave differently as the universe expands.
The research shows that while the universe’s total entropy continues to increase in accordance with the second law of thermodynamics, the entropy per unit volume gradually decreases over time. This distinction may provide a new way of understanding how localized structures can become increasingly organized even as the universe as a whole moves toward greater entropy.
Within the model, the local geometric properties of spacetime satisfy a version of the first law of thermodynamics. The study interprets the theory’s dynamic dark energy contribution as a form of internal energy, while identifying Quantum Geometric Relative Entropy as the local entropy density.
The framework also naturally produces effective temperature and pressure, suggesting that the underlying quantum state described by the theory may possess an inherent thermal character.
Building on Decades of Black Hole Research
The relationship between gravity and thermodynamics has been an active area of research for decades. In the 1970s, pioneering work by Jacob Bekenstein and Stephen Hawking demonstrated that black holes possess entropy and emit thermal radiation, revealing a profound connection between gravity, information, and thermodynamics.
Professor Bianconi’s work builds on those ideas by extending thermodynamic principles to the broader structure of spacetime itself.
The study also emphasizes the importance of the local volume element defined by the physical spacetime metric. As the universe expands, this volume grows, leading to increasing total entropy while simultaneously reducing the local Quantum Geometric Relative Entropy per unit volume. According to the researchers, this distinctive thermodynamic behavior is a defining feature of the Gravity from Entropy framework.
Implications for Cosmology and Fundamental Physics
Although the theory remains in an early stage of development, the findings suggest new ways to connect several major areas of physics, including general relativity, quantum mechanics, thermodynamics, and cosmology.
By proposing that gravity and spacetime possess intrinsic informational and thermodynamic properties, the research offers a possible framework for understanding how increasing complexity can emerge without contradicting the second law of thermodynamics.
As Professor Bianconi explains, “This work reveals how the Gravity from Entropy theory can tackle the challenging question of reconciling the second law of thermodynamics with the emergence of complexity in our universe. These results may open new avenues for investigating the long-standing problem of reconciling the foundations of cosmological irreversibility, the emergence of complex structures and ultimately life with fundamental gravitational dynamics.”
While additional theoretical development and future observational testing will be needed, the study presents a promising avenue for exploring some of the deepest unanswered questions about the origin, evolution, and underlying physics of the universe.
Herman Melville is a contributor at TechNewsInc, covering a diverse range of topics including news, politics, business, technology, sports, entertainment, and lifestyle. He focuses on clear, reliable reporting and useful information, helping readers stay informed about current affairs and developments through relevant, accessible, and engaging stories.
